Combination switch for the control of electrothermal apparatus



E. CHALLET 2,318,055 THE CONTROL OF ELECTRO-THERMAL APPARATUS May 4, 1943.

COMBINATION SWITCH FOR Filed Sept. 18, 1941 Patented May 4, 1943 UNITED STATES PATENT OFFICE COMBINATION SWITCH FOR THE CONTROL OF ELECTROTHERMAL APPARATUS of Switzerland Application September 18', 1941, Serial No. 411,423 In Switzerland June 23, 1941 1 Claim.

The object of the present invention, which is due to Mr. Etienne Challet, is related to a combination-switch for the control of electro-thermal apparatuses, comprising contacting segments mounted on a common rotary spindle for cooperating with fixed brushes in combining and switching on and ofi at least two resistances, in which it is claimed that contacting segments are built over different angles, so that when said resistances are combined in parallel and must be switched off, resistances are cut ofi one after another.

The attached drawing shows for instance a form of construction of the object of the invention. In Fig. 1, it is shown in elevation. Fig, 2 is a horizontal section along AA of Fig. 1, and Fig. 3 is an enlarged cross-section along B--B of Fig, 1. Fig. 4 is a schematic diagram.

The form of construction as shown comprises a base I of insulating material onto which is fixed a metallic frame 2. In this frame, above the base, is mounted a rotary spindle 3 on which are fixed two independently insulated rings 4 with gorge-shaped contacting surface. On both sides of these rings are fixed contacting segments 5. the relative angular position of which is shown schematically on Fig. 4.

In the position designated on Fig. 4 by its angle of rotation of 270 degrees from the ofi position, contacting segments are brought to cooperate with three brushes I, II and L. These contacting segments are shown in elevation in the upper part of Fig. 1 and in plan view on the axis of Fig. 2. The two outer ones among these contacting segments are built over the same angle as the contacting segments 5 in other positions. whereas the middle one 5a is only built over an appreciably smaller angle.

The base I is also provided on both sides with terminals that extend upwards with brushes. On one side are two brushes 6 connected to the current supplying leads of the apparatus. These brushes have a toriodally shaped piece of contact that engages into the gorge of rings 4. On the other side of the base are three brushes I,

II and L, which are connected to the heating resistances of the apparatus. These brushes have a U-shaped piece of contact for cooperating with the contacting segments 5.

On one of the ends of the spindle 3, which extends outside of the frame and presents a square for adapting the control knob, there is also a cam 1 shaped with four concave stops at degrees from one another and separated by rounded tops. On both sides of this cam, in the same plane, are mounted two levers 8, the upper ends of which are pivoted on the frame While their lower ends are linked together by a tension spring I0. In their middle, these levers are fitted with a roller 9 corresponding with the stops in the cam. Outside the stops, these rollers act on the cam as a rotation torque, so that the rotary spindle always stops in the required positions as shown on Fig 4.

In the ofi position, at 0 degrees, the resistances are not in circuit. At 90 degrees, resistances I and II are combined in series. At degrees, resistance I alone is in circuit. Finally, at 270 degrees, resistances I and II are combined in parallel. The contacting segment 5a, which, in this position, cooperates with brush II, is built over a smaller angle than the contacting segment 5 cooperating with brush 1. When switching ofi from that position, therefore, resistance I is always cut off after resistance II.

I claim:

In a control-switch for electro-thermal apparatuses, comprising a base carrying a frame, fixed brushes mounted on said base, several contacting sequents of same length mounted on a common rotary spindle rotatable in said frame and cooperating with said brushes in combining and in switching on and out at least two resistances, in combination, one at least additional contacting segment of smaller length, so that when said resistances are combined in parallel and must be switched off simultaneously, these resistances are cut out quickly one after another in one single operation.

ETIENNE CHALLET. 

